System of locomotive control.



F. w MEYER.

SYSTEM OF LOCOMOTIVBCONTROL APELICATIDN FILED MAR. 24. 1915.-

Pzitntedlug. 13, 1918.

2 SHEEISSHEET 1- 'INVENTOR F. w. MEYER. SYSTEM OF LOCOMOTIVE CONTROL.

I a APPL'CATON FILED "AR-2M 1915- 1,275,969. Patented Aug. 13,1918. 2SHE ETS'SHEET 2.

7 ATTORNEY UNITED s'r rns PATENT curios.

FRIEDRICH w. MEYER, or PITTSBURGH, rnnnsrnyamansslonon '10 wns'rnre-HOUSE ELECTRIC AND MANUFACTURING COMPANY, A conrona'non or PENN-SYLVANIA.

To all whom t'tmuy concern Be it known that I, FRIEDRICH W. a subject ofthe Emperor of Germany, and

a resident of Pittsburgh, inthe count Allegl'leny and State ofPennsylvania, ave

MEYER,-

Speoiflcation of Letters Patent.

invented a new and useful Improvement in Systems of Locomotive Control,of which the followingas a spec-lfication.

My invention relatesto electric. railway systems, and it has for itsobject to provide means whereby electric locomotives, especially thoseof the split-phasetype, may be conveniently started and whereb' thespeed, power factor and load distribution in a plurality of motors maysubsequently be regulated.

In the accompanying drawing Figure 1 is a diagrammatic view of theelectrical equip-- ment of a railway vehicle provided with one form ofmy invention; and Fig. 2 is a diagrammatic view of a modification of theequipment shownin Fig. 1.

In the operation of electric railway systems, it is desirable to employsingle-phase l'iigh-voltage distribution in the line for reasons ofeconomy but no single-phase al tcrnatingecurrent motor has as yet beendeveloped which is entirely satisfactory for heavy tractionpurposes. Ithas, therefore, been proposed to employ polyphase induction motors forpropulsion and to convert energy derived from. the line into a formsuitable for the supply of the motors by a phase splittini device,preferably of the rotary type. s phase-splitting devices of thischaracter have the starting character istics of single-phase motors, itis generally necessary to provide them with auxiliary startingapparatus. The poly hase induc- 0 tion motor is essentially a sing e-seed machine and, inorder to provide flexi le speed regulation therefor,it has been a common ractice to provide cascading arran ements inconnection with adjustable secon ary re sistance members, with attendantheavy losses. It" is; therefore, desirable to equip a railway'yehiclewith energy changing apparatus, whereby cnerg. derived from thesecondary members of t e induction motors in the speed regulationthereof may be returned to the primary windings. Furthermore, it isextremely difiicult to maintain the SYSTEM OF LOCOMOTIVE CONTROL.

Patented Aug. 13, 1918.

Application'flled Batch 2 1, 1915. Ser1alNo.16,883. a

such, r example, as a locomotive, at the same (llameters because ofuneven wear and because of the heavy machining necessary,

in some cases, to remove defects, such as flaws and flat spots. As aresult, the inducdriving wheels of a heavy electric vehicle,

the motors, with resultant unequal distribution of the loadand seriousheating in the overloaded motors. It is desirable, there fore, toequipthe vehicle with apparatus for power-equalizing urposes and, inaddition,

apparatus should e installed for improving the power factorin the motorsfor 'econom in power transmission; By my invention, I provide one, or atthe most, two setsof auxiliary apparatus on a railway vehicle which willaccomplish all of the above-mentio'ned results in an effective manner,with considerable saving in weight and complexity of circuits.Furthermore, the ar rangementis such that I may conveniently increase'the starting torque through the op- I eration of the auxiliary apparatusdirectly on propulsion wheels, thus permitting the use of smallerpropulsion motors.

Referring to the form of my invention shown in Fig. 1, a single-phasehigh-voltage trolley line supplies energy to the primary winding of avehicle transformer 4 throng a suitable contact device 5. A phaseconverter or phase splitterlS of the rotary type derives energy from thesecondary wlndin of the transformer 4 and supplies sai energy, in theform of. polyphase current,

to the primary windings 2 of polyphase propulsion motors of theinduction type through suitable mains 8. The secondary members of themotors 6 and 7 are of the wound type and supply 'ener through suitableslip rings, to two.polyp ase transs formers 9 and 10 connected, in turn,to two polyphase commutator motors 11 and'12.

- The machines 11 and 12 are mounted on the shaft of the phase converter13 solgthat,

under certain conditions, they may assist driving the same and, underother (Quilltions, may derive mechanical energythsrenected in star tothe supply from. Each of the machines 11 and 12 is provided witharmature windings connected to a commutator; 14:. T lie-three brushes 16bear upon each of the commutators 1 1 at points 120 electrical degreesapart and are connected to theslip rings of the secondary windingsofvthe motors 6 and 7 through the adjustable transformers 9 and 10.Compensating windings 19 are connected between each of the brushes 16and their respective supply mains for assistance in commutation.Suitable working windings 20 are conmains of the machines 11 and 12, thestar relation being achieved, in each case, by a bond wire 21 suitablyconnected, the respective windings-by adjustable taps 22,22. Each of thewindings 20'derives energy from its respective main, through anadjustable rheostat 23, connection between the rheostat and the windingbeing made by adjustable tap members 24. 1

Having thus described the structure ,of my invention, the operation isas follows: The phase converter 5 may be either of the self-startingtype or it may be brought up to speed by a special starting motor or bythe application of single-phase current from the source of supply to oneof the machines 11 and 12. As a result, of the operation of the phaseconverter 13, polyphase current 'is supplied through the mains 8 to thepri mary windings of the propulsion motors 6 and 7. At the start, a highsecondary voltage is desired in the propulsion motors, and the ratio oftransformation of the transformers 9 and 10 is therefore set at a lowwith consequent adjustment 'of the power factor of the machines 6 and 7and, by the adjustmentlof the rheostats 23, the strength of themagnetizing fields in the machines. 11 and 12 may be changed for loadequalization. slightly under siz should have its speed slightlyincreased for proper load distribution; Its secondary energy outputshould therefore be decreased, and'the correspondto an oversize drivershould be excited to exert; slightly over-normal driving torque.

The motor connected to a drive wheel whereas that in the machineexerting large driving torque would have a large watt com ponent.

Furthermore, the fact. that a polyphase' e'ommutator machine can operateeither as a motor or as a generator enables one to obtain a flexiblearrangement with but small auxiliary machines. For example, when runningat or near synchronism, themachine associated with a propulsion motorcoupled to an .undersize driver may be operated as a '80 a generator andsupplying energy .to the induction motor secondary for over-synchronousoperat1on, while the auxiliary machine ,assoclated with a motor coupledto an oversize driver'maybe operating as a motor and, 8 5

deriving energy from the Induction motior' secondary member forunder-synchronous operation. Referring to the shown in F i 2, energvehicle trans or'mer 25 from a sing e-phase line 26 and flows to a phasesplitter 27 or any suitable form where it is converted into polyphase-current for supply to theprimary form of my invention issuppliedto a windings of polyphase sropulsionmotors 28 9 5- of the inductiontype. urrent derived from the secondary members of the motors 28 throughsuitable slip rings 29' issupplied fto polyphase. commutator machines30, in

general form similar tothe machines 11 and 12 in Fig. 1; The machines30-30 are oir pled to pony wheels 31 for a double purpose to behereinafter pointed out. Current derived fromthe machines 30-30 may bturned to the p ly uses ofth'e machines' lob 28 through suita leadjustable transformers The fields of'the machines 30-4-30 differ fromthose of the machines 11 and 12 of Fig. 1 in that the magnetizingwindings rather than star 110.

thereof are delta connected connected.

In-the operation of the device shown in Fig. 2, the phase-splitter 27 isbrought up to speed in any desired manner and, thereupon,

supplies polyphase current to the motorslld The transformers 3232 areini maider thereof returns to the supply buses 12B of themzwhines 28-28through the transformers As in the circuit of Fig. 1, adjustment in thepower factor of the motors 2828 may be made by shifting the A portion aax'cs of the fields'of the magnetizing wind- 1 30 ings'of the machines30 30, and uneven dis tribution of the load between the motors 28-28,arising from unequal wheel d1ameters, may be accurately compensated forby.

secondary members through the auxiliary machines.

While I. have shown my invention in two distinct embodiments only, itwill be apparout to those skilled in the art that it is suseeptible ofvarious minor changes and modifications without departin from the spiritthereof and I desire, there ore, that no limitations shall be placedthereupon except such as are imposed by the prior art or arespecifically set forth in the appended claims.

I claim as my invention:

, f 1. I analternati'ng-current system of distiibutio ,the' combinationwith a source of alternating current of} one phase-number, of

an induction motor oianother phase numbenjaphaseconverter forderivingcurrents from said source-suitable for application to saidmotor, and means for deriving energy from the secondary member of saidinduction motor in the speed variation thereof and for returning saidenergy to the system through said haseconverter.

2. ii an alternating-current system of distribution, the combinationwith a source of alternating current of one phase-number, of

an. induction motor of another phase-number, a rotary phase-converterfor deriving currents from said source suitable for application to saidmotor, an alternating-current commutator machine mechanically coupled tothe shaft of said phase-converter, and an- .6 adjustable transformerconnected between tion thereof and for returning said energy 5 properadjustment of the strength of the single-phase alternating current, of apolyworking. fields of the machines 30-30 and phase induction motor, arotary phase-conof the ratios of transformation of the transverterfor-deriving currents from said source formers 32"32,- suitable forapplication to said motor, an If desired, the auxiliary machines 30-430alternating current commutator machine 10 in Fig. 2 may be merelpolyphase motors, mechanica ly coupled to the shaft of said as employedin Fig. 1. n this case, the 8650- base converter, and an adjustabletransondary energy of the main motors is obnormer connected between thesecondary verted into mechanical power for applicawinding of saidinduction motor and said tion to the pony axle, rat or than appearingcommutator machine, whereby ener may 15 at the polyphase buses. beinterchanged between said induction mo- 0 Attention is directed to thefact that with tor and said phase-converter. the circuits of 2,over-synchronous 5. In an alternating-current system of disspeed may bereadily obtained in the motors tribution, the combination with a sourceof 28- 28by deriving current from the polysingle-phase alternatingcurrent, of a poly- 20 phase buses and supplying it to the motor phaseinduction motor, a rotary phase-converter for deriving currents fromsaid source suitable for application to said motor, an alternatingcurrent commutator machine mechanically coupled to the shaft of saidphaseconverter, an adjustable transformer connected between thesecondary winding of said induction motor and said commutator machine,whereby energy may be interchanged between said induction motor and saidphase-converter, and means for varying the field of said polyphasecommutator machine to adjust the power factor of the system. i

6. In an alternating-current system of distribution, the combinationwith a source of single-phase alternating-current, of a plurality ofpolyphase induction motors, a phase-converter for deriving currents fromsaid source suitable for application to said motors, and means forinterchanging energy between. the secondary members of said in ductionmotors for load equalization there" I -tribution, the combination with asource of single-phase alternatin current, of a plurality of polyphasein notion motors, a rotary phase-converter for deriving currents machineelectrically connected to the secfrom, said source suitable 'forapplication to said motors, and a polyphasecommutator V 60single-phase'alternating current, of a poly- 1 ,the secondary winding ofsaid induction mo- 55 tor and said commutator machine, whereby energymay be interchanged between said induction motor and saidphase-converter.

3. In an alternating-current system of distnibution, the combinationwith a source of ondary member of each induction motor, respectivel andmechanically coupled to said rotary p ase converter,'whereby energyderived from under-loaded motors is transferred to overloaded motorsfor'load equalization.

8. The method of operating a plurality of induction motors subject tounequal loads and deriving energy from a source of alternatmg currentthrough a dynamo-electric phase-converter, both the primary andsecondary members of said motors being dyphase induction motor, aphase-converter for deriving current from said source suitable forapplication to said motor, and means for deriving energyfrom thesecondary member W ofsaid induction motor in the speed varianami'ca lly;connected to said phase-converter, the loads on said mot ors my besubstantially which comprises transferring energy from equalized. thesecondary member of an under-loaded In testimony whereof I have hereuntosubmotor to the secondary member of an overscribed m name this 12th dayo f Mareh,

5 leadedw'motor, when said motors are operat- 1915.

ilrg near synchronisln, and transferring unequal amounts of energybetween the sec FRIEDRICH MEYER on'dery members ofsa'id'two motors andsaid Witnesses: source through said. phase-converter when D. C. DAvis,

10 operatingaway from synchronism, whereby B. B. Hume.

